Field of the Invention
The present invention relates to a temperature adjustment apparatus for adjusting the temperature of a control object using a Peltier element.
Description of the Related Art
Heretofore, for example, as disclosed in Japanese Patent No. 3660963 (hereinafter referred to as the “conventional technique”), a temperature adjustment apparatus is known that adjusts the temperature of a control object using a Peltier element. With such a temperature adjustment apparatus, a temperature sensor detects the temperature of the control object, a temperature regulator outputs an operating quantity for adjusting the detected temperature to a desired temperature, and a drive circuit drives a Peltier element at an output amount that is proportional to (dependent on) the operating quantity.
In this case, within a region where the absolute value of the operating quantity is low, a time-based proportional control (PWM control) is carried out in which a pulse voltage of the same voltage value is applied repeatedly to the Peltier element. On the other hand, within a region where the absolute value of the operating quantity is high, a variable voltage control is carried out in which a DC voltage, the magnitude of which can be adjusted, is applied continuously to the Peltier element.